The Underlying Mechanism Involved in Gefitinib Resistance and Corresponding Experiment Validation in Lung Cancer.

Background: Gefitinib resistance remains a major problem in the treatment of lung cancer. However, the underlying mechanisms involved in gefitinib resistance are largely unclear. Methods: Open-accessed data of lung cancer patients were downloaded from The Cancer Genome Atlas Program and Gene Expression Omnibus databases. CCK8, colony formation, and 5-ethynyl-2'-deoxyuridine assays were utilized to evaluate the cell proliferation ability. Transwell and wound-healing assays were utilized to evaluate the cell invasion and migration ability. Quantitative real-time PCR was utilized to detect the RNA level of specific genes. Results: Here, we obtained the expression profile data of wild and gefitinib-resistant cells. Combined with the data from the TCGA and GDSC databases, we identified six genes, RNF150, FAT3, ANKRD33, AFF3, CDH2, and BEX1, that were involved in gefitinib resistance in both cell and tissue levels. We found that most of these genes were expressed in the fibroblast of the NSCLC microenvironment. Hence, we also comprehensively investigated the role of fibroblast in the NSCLC microenvironment, including its biological effect and cell interaction. Ultimately, CDH2 was selected for further analysis for its prognosis correlation. In vitro experiments presented the cancer-promoting role of CDH2 in NSCLC. Moreover, cell viability detection showed that the inhibition of CDH2 could significantly decrease the IC50 of gefitinib in NSCLC cells. GSEA showed that CDH2 could significantly affect the pathway activity of PI3K/AKT/mTOR signaling. Conclusions: This study is aimed at investigating the underlying mechanism involved in gefitinib resistance to lung cancer. Our research has improved researchers' understanding of gefitinib resistance. Meanwhile, we found that CDH2 could lead to gefitinib resistance through PI3K/AKT/mTOR signaling.

MiR-4739 inhibits the malignant behavior of esophageal squamous cell carcinoma cells via the homeobox C10/vascular endothelial growth factor A/phosphatidylinositol 3-kinase/AKT pathway.

Esophageal cancer is a lethal disease, and emerging evidence has shown that microRNAs are involved in its development, progression, and clinical outcome. MicroRNAs are potential biomarkers for esophageal squamous cell carcinoma (ESCC), and may be useful in advanced RNA therapy for ESCC. This study was conducted to evaluate the molecular mechanism of miR-4739 in ESCC. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to measure RNA and protein levels. Transwell assay, Cell Counting Kit-8 assay, cytometry analysis, and human umbilical vein endothelial cell tube formation assay were conducted to determine the molecular function of miR-4739 in ESCC. Potential targets of miR-4739 were predicted using bioinformatics tools and confirmed in ESCC cells using a luciferase reporter and RNA pulldown assay. Finally, we performed immunohistochemistry to evaluate the effects of administering agomir-4739 to a mouse model of ESCC. MiR-4739 expression was downregulated in ESCC tissues and cells. MiR-4739 overexpression inhibited cell proliferation, migration, and invasion, and promoted apoptosis of ESCC cells. Furthermore, vascular endothelial growth factor A expression was downregulated by miR-4739 mimics in ESCC cells. MiR-4739 negatively regulated homeobox C10 expression. Additionally, agomir-4739 inhibited tumor growth and angiogenesis in vivo. We demonstrated that miR-4739 overexpression exerted an inhibitory effect on ESCC cells by preventing the expression of homeobox C10 via the vascular endothelial growth factor A/phosphatidylinositol 3-kinase/AKT pathway, indicating the potential of this microRNA as a treatment target in ESCC.

Feasibility evaluation of the transapical saddle-shaped valved stent for transcatheter mitral valve implantation.

BACKGROUND AND AIMS OF STUDY: Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high-risk mitral regurgitation. We aimed to investigate the feasibility of a novel self-expanding valved stent for TMVI via apical access. METHODS: We designed a novel self-expanding mitral valve stent system consisting of an atrial flange and saddle-shaped ventricular body connected by two opposing anchors and two opposing extensions. During valve deployment, each anchor was controlled by a recurrent string. TMVI was performed in 10 pigs using the valve prosthesis through apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. Surviving pigs were killed 4 weeks later to confirm stent deployment. RESULTS: Ten animals underwent TMVI using the novel mitral valve stent. Optimal valve deployment and accurate anatomical adjustments were obtained in nine animals. Implantation failed in one case, and the animal died 1 day later due to stent mismatch. After stent implantation, the hemodynamic parameters of the other animals were stable, and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract were 2.98 ± 0.91 mmHg and 3.42 ± 0.66 mmHg, respectively. Macroscopic evaluation confirmed the stable and secure positioning of the stents. No obvious valve displacement, embolism, or paravalvular leakage was observed 4 weeks postvalve implantation. CONCLUSIONS: This study demonstrated that the novel mitral valve is technically feasible in animals. However, the long-term feasibility and durability of this valved stent must be improved and verified.

Effects of Preserving the Pulmonary Vagus Nerve Branches on Cough After Pneumonectomy During Video-Assisted Thoracic Surgery.

Background: Cough is one of the most common complications of early-stage non-small cell lung cancer (NSCLC) after video-assisted thoracoscopic surgery (VATS). The vagus nerve plays an important role in pulmonary inflammation and the cough reflex. In this study, we attempted to reduce the incidence of postoperative chronic cough and other complications by preserving the pulmonary vagus nerve branches. Patients and Methods: This study was a randomized controlled double-blinded trial of subjects and observers. A total of 158 NSCLC patients were enrolled. We randomly assigned 79 patients to Group A (pulmonary branch of vagus nerve preservation group) and 79 cases to Group B (conventional surgical treatment group). In the final analysis, 72 patients from Group A and 69 patients from Group B were included. The main outcome measure of the study was the occurrence of CAP or other postoperative complications within five weeks. This trial was registered with ClinicalTrials.gov (number NCT03921828). Results: There was no significant difference in preoperative general clinical data between the two groups. No death during the perioperative period occurred in either of the two groups. There was no significant difference between the two groups in operation time, intraoperative bleeding, number of lymph nodes sent for examination, number of cases transferred to ICU after operation, postoperative catheterization time, or postoperative hospital stay (P>0.05). There was no significant difference in other pulmonary and cardiovascular complications between the two groups, including pulmonary infection (2.78% vs. 8.70%, P = 0.129), atelectasis (1.39% vs. 0%, P = 0.326), pleural effusion (2.78% vs. 1.45%, P = 0.585), persistent pulmonary leakage (2.78% vs. 2.90%, P = 0.965), arrhythmia (2.78% vs. 1.45%, P = 0.585), and heart failure (0% vs. 1.45%, P = 0.305). The incidence of CAP in Group A was significantly lower than that in Group B (13.89% vs. 30.43%, P = 0.018). The LCQ-MC scores in Group A were significantly higher than those in Group B at two and five weeks after operation (P<0.05). Univariate and multivariate analysis showed that the risk factors for postoperative CAP were surgical side (right lung), surgical lung lobe (upper lobe), preservation of pulmonary branch of the vagus nerve during operation, and duration of anesthesia. Conclusions: Preserving the pulmonary vagus nerve branches during VATS in patients with stage IA1-2 NSCLC can reduce the incidence of postoperative CAP.

PTBP3 mediates TGF-ß-induced EMT and metastasis of lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is associated with a poor prognosis due to early metastasis to distant organs. TGF-ß potently induces epithelial-to-mesenchymal transition (EMT) and promotes invasion and metastasis of cancers. However, the mechanisms underlying this alteration are largely unknown. PTBP3 plays a critical role in RNA splicing and transcriptional regulation. Although accumulating evidence has revealed that PTBP3 exhibits a pro-oncogenic role in several cancers, whether and how PTBP3 mediates TGF-ß-induced EMT and metastasis in LUAD remains unknown. The expression levels and prognostic value of PTBP3 were analyzed in human LUAD tissues and matched normal tissues. siRNAs and lentivirus-mediated vectors were used to transfect LUAD cell lines. Various in vitro experiments including western blot, qRT-PCR, a luciferase reporter assay, chromatin immunoprecipitation (ChIP), transwell migration and invasion assay and in vivo metastasis experiment were performed to determine the roles of PTBP3 in TGF-ß-induced EMT and metastasis. PTBP3 expression was significantly upregulated in patients with LUAD, and high expression of PTBP3 indicated a poor prognosis. Intriguingly, we found that PTBP3 expression level in LUAD cell lines was significantly increased by exogenous TGF-ß1 in a Smad-dependent manner. Mechanistically, p-Smad3 was recruited to the PTBP3 promoter and activated its transcription. In turn, PTBP3 knockdown abolished TGF-ß1-mediated EMT through the inhibition of Smad2/3 expression. Furthermore, PTBP3 overexpression increased lung and liver metastasis of LUAD cells in vivo. PTBP3 is indispensable to TGF-ß-induced EMT and metastasis of LUAD cells and is a novel potential therapeutic target for the treatment of LUAD.

GDF11 alleviates neointimal hyperplasia in a rat model of artery injury by regulating endothelial NLRP3 inflammasome activation and rapid re-endothelialization.

BACKGROUND: Neointimal hyperplasia induced by interventional surgery can lead to progressive obliteration of the vascular lumen, which has become a major factor affecting prognosis. The rate of re-endothelialization is known to be inversely related to neointima formation. Growth differentiation factor 11 (GDF11) is a secreted protein with anti-inflammatory, antioxidant, and antiaging properties. Recent reports have indicated that GDF11 can improve vascular remodeling by maintaining the differentiated phenotypes of vascular smooth muscle cells. However, it is not known whether and how GDF11 promotes re-endothelialization in vascular injury. The present study was performed to clarify the influence of GDF11 on re-endothelialization after vascular injury. METHODS: An adult Sprague-Dawley rat model of common carotid artery balloon dilatation injury was surgically established. A recombinant adenovirus carrying GDF11 was delivered into the common carotid artery to overexpress GDF11. Vascular re-endothelialization and neointima formation were assessed in harvested carotid arteries through histomolecular analysis. CCK-8 analysis, LDH release and Western blotting were performed to investigate the effects of GDF11 on endothelial NLRP3 inflammasome activation and relevant signaling pathways in vitro. RESULTS: GDF11 significantly enhanced re-endothelialization and reduced neointima formation in rats with balloon-dilatation injury by suppressing the activation of the NLRP3 inflammasome. Administration of an endoplasmic reticulum stress (ER stress) inhibitor, 4PBA, attenuated endothelial NLRP3 inflammasome activation induced by lysophosphatidylcholine. In addition, upregulation of LOX-1 expression involved elevated ER stress and could result in endothelial NLRP3 inflammasome activation. Moreover, GDF11 significantly inhibited NLRP3 inflammasome-mediated endothelial cell pyroptosis by negatively regulating LOX-1-dependent ER stress. CONCLUSIONS: We conclude that GDF11 improves re-endothelialization and can attenuate vascular remodeling by reducing endothelial NLRP3 inflammasome activation. These findings shed light on new treatment strategies to promote re-endothelialization based on GDF11 as a future target.

CircRNA-DOPEY2 enhances the chemosensitivity of esophageal cancer cells by inhibiting CPEB4-mediated Mcl-1 translation.

BACKGROUND: Cisplatin-based chemotherapy is a mainstay systematic therapy for advanced esophageal squamous cell carcinoma (ESCC), and cisplatin resistance, which is not uncommon, is the major barrier to improving patient outcomes. Circular RNAs (circRNAs) are novel noncoding RNAs that are implicated in cancer progression, but their involvement in modulating cisplatin responsiveness in ESCC remains unknown. METHODS: Bioinformatics analysis was used to profile and identify the circRNAs involved in cisplatin responsiveness in ESCC. The chemosensitive role of cDOPEY2 was confirmed both in vitro and in vivo. The molecular mechanism of cDOPEY2 was investigated by mass spectrometry, immunoprecipitation, and ubiquitination analyses. RESULTS: We report that a novel circRNA (cDOPYE2, hsa_circ_0008078) was markedly downregulated in cisplatin-resistant ESCC cells (ESCC-CR) compared with parental chemosensitive cells. Re-expression of cDOPEY2 substantially enhanced the cell-killing ability of cisplatin by augmenting the apoptotic process in ESCC-CR cells, which was achieved by decreasing the abundance of the antiapoptotic protein Mcl-1. Mechanistically, we showed that cDOPEY2 acted as a protein scaffold to enhance the interaction between the cytoplasmic polyadenylation element binding protein (CPEB4) and the E3 ligase TRIM25, which in turn facilitated the ubiquitination and degradation of CPEB4. The increased Mcl-1 expression in ESCC-CR cells was dependent on the binding of CPEB4 to its untranslated mRNA, and depletion of CPEB4 mediated by cDOPEY2 reversed this effect. Rescue experiments confirmed that the critical role of cDOPEY2 in maintaining cisplatin sensitivity was dependent on the depletion of CEPB4 and its downstream target Mcl-1. Clinical and in vivo data further corroborated the significant relevance of cDOPEY2 to cisplatin responsiveness in ESCC. CONCLUSIONS: We provide evidence that cDOPEY2 inhibits CPEB4-mediated Mcl-1 translation by promoting the ubiquitination and degradation of CPEB4 to alleviate cisplatin resistance, indicating that cDOPEY2 may serve as a valuable biomarker and potential therapeutic target in ESCC.

Upregulation of glucosamine-phosphate N-acetyltransferase 1 is a promising diagnostic and predictive indicator for poor survival in patients with lung adenocarcinoma.

Lung adenocarcinoma, a type of non-small cell lung cancer, is the leading cause of cancer death worldwide. Great efforts have been made to identify the underlying mechanism of adenocarcinoma, especially in relation to oncogenes. The present study by integrating computational analysis with western blotting, aimed to understand the role of the upregulation of glucosamine-phosphate N-acetyltransferase 1 (GNPNAT1) in carcinogenesis. In the present study, publicly available gene expression profiles and clinical data were downloaded from The Cancer Genome Atlas to determine the role of GNPNAT1 in lung adenocarcinoma (LUAD). In addition, the association between LUAD susceptibility and GNPNAT1 upregulation were analyzed using Wilcoxon signed-rank test and logistic regression analysis. In LUAD, GNPNAT1 upregulation was significantly associated with disease stage [odds ratio (OR)=2.92, stage III vs. stage I], vital status (dead vs. alive, OR=1.89), cancer status (tumor status vs. tumor-free status, OR=1.85) and N classification (yes vs. no, OR=1.75). Cox regression analysis and the Kaplan-Meier method were utilized to evaluate the association between GNPNAT1 expression and overall survival (OS) time in patients with LUAD. The results demonstrated that patients with increased GNPNAT1 expression levels exhibited a reduced survival rate compared with those with decreased expression levels (P=8.9×10-5). In addition, Cox regression analysis revealed that GNPNAT1 upregulation was significantly associated with poor OS time [hazard ratio (HR): 1.07; 95% confidence interval (CI): 1.04-1.10; P<0.001]. The gene set enrichment analysis revealed that 'cell cycle', 'oocyte meiosis', 'pyrimidine mediated metabolism', 'ubiquitin mediated proteolysis', 'one carbon pool by folate', 'mismatch repair progesterone-mediated oocyte maturation' and 'basal transcription factors purine metabolism' were differentially enriched in the GNPNAT1 high-expression samples compared with GNPNAT1 low-expression samples. The aforementioned pathways are involved in the pathogenesis of LUAD. The findings of the present study suggested that GNPNAT1 upregulation may be considered as a promising diagnostic and prognostic biomarker in patients with LUAD. In addition, the aforementioned pathways may be pivotal pathways perturbed by the abnormal expression of GNPNAT1 in LUAD. The findings of the present study demonstrated the therapeutic value of the regulation of GNPNAT1 in lung adenocarcinoma.

Long Noncoding RNA FAM225A Promotes Esophageal Squamous Cell Carcinoma Development and Progression via Sponging MicroRNA-197-5p and Upregulating NONO.

Esophageal squamous cell carcinoma (ESCC) is the major subclass of esophageal cancer and one of the most life-threatening malignancies with high morbidity and mortality. Long noncoding RNAs (lncRNAs) participate in tumorigenesis and metastasis of various tumors. Here, we investigated the function of a newly identified lncRNA FAM225A in ESCC. LncRNA FAM225A expression was significantly higher in ESCC and predicted poor prognosis of ESCC patients. We confirmed that upregulation of FAM225A in ESCC and overexpression of FAM225A was associated with poor outcome in ESCC patients using TCGA ESCC cohort. Knockdown of FAM225A significantly inhibited cell growth, migration and invasion of ESCC cells in vitro and inhibited ESCC xenograft development in vivo. Mechanistically, we demonstrated that lncRNA FAM225A functioned as a competing endogenous RNA (ceRNA) via sponging miR-197-5p. LncRNA FAM225A exerted its regulatory function on ESCC proliferation and metastasis via modulating expression of miR-197-5p. MiR-197-5p overexpression antagonized the function of FAM225A, with decreased cell growth and invasion. Moreover, we identified that RNA binding protein NONO was a direct target of miR-197-5p and miR-197-5p negatively regulated NONO expression and TGF-ß signaling in ESCC cells. In summary, our findings suggest that lncRNA FAM225A promotes ESCC development and progression via sponging miR-197-5p and upregulating NONO expression. These results suggest that lncRNA FAM225A could be explored as a new therapy target in ESCC treatment.

Transcatheter Mitral Valve Replacement for Treating Native Mitral Valve Disease: Current Status.

Transcatheter mitral valve replacement is increasingly being used as a treatment for high-risk patients who have native mitral valve disease; however, no comprehensive studies on its effectiveness have been reported. We therefore searched the literature for reports on patients with native mitral valve disease who underwent transcatheter access treatment. We found 40 reports, published from September 2013 through April 2017, that described the cases of 66 patients (mean age, 71 ± 12 yr; 30 women; 30 patients with mitral stenosis, 34 with mitral regurgitation, and 2 mixed) who underwent transcatheter mitral valve replacement. We documented their baseline clinical characteristics, comorbidities, diagnostic imaging results, procedural details, and postprocedural results. Access was transapical in 41 patients and transseptal in 25. The 30-day survival rate was 82.5%. The technical success rate (83.3% overall) was slightly but not significantly better in patients who had mitral regurgitation than in those who had mitral stenosis. Transapical access procedures resulted in fewer valve-in-valve implantations than did transseptal access procedures (P=0.026). These current results indicate that transcatheter mitral valve replacement is feasible in treating native mitral disease. The slightly higher technical success rate in patients who had mitral regurgitation suggests that a valve with a specific anchoring system is needed when treating mitral stenosis. Our findings indicate that transapical access is more reliable than transseptal access and that securely anchoring the valve is still challenging in transseptal access.

MiR-92a regulates endothelial progenitor cells (EPCs) by targeting GDF11 via activate SMAD2/3/FAK/Akt/eNOS pathway.

BACKGROUND: The effects of miR-92a on EPCs are still poorly elucidated. This study aimed to investigate the effects of miR-92a on EPCs (Endothelial progenitor cells) in a model of hypoxia (HO) or high glucose (HG)-induced EPCs injury by targeting GDF11 (Differentiation growth factor 11). METHODS: The effects of miR-92a on EPCs subjected to HO or HG were investigated firstly. Subsequently, the action mechanism of miR-92a on EPCs by targeting GDF11 was elucidated. Proliferation, apoptosis, migration, angiogenesis was measured with MTT, flow cytometry, transwell, tube formation respectively. After 24 h, levels of reactive oxygen species (ROS) were measured by fluorescence intensity. LDH and NO (nitric oxide) levels were determined by ELISA. The expression of FLK-1 (fetal liver kinase 1) and vWF (von Willebrand factor) was detected by immunofluorescence. mRNA and protein expression levels were examined using PCR and western blotting respectively. The interaction between miR-92a and GDF11 was evaluated by dual-luciferase reporter assay. RESULTS: Our results showed that HO or HG increased apoptosis, production of LDH and generation of ROS, but decreased the ability of migration and tube formation and generation of NO in EPCs; inhibiting of miR-92a decreased HO or HG-induced injury of EPCs, whereas miR-92a over-expression had the opposite effect; the protective effects induced by inhibiting of miR-92a on EPCs could be reversed by GDF11 siRNA and the harmful effects induced by over-expression of miR-92a could be rescued by over-expression of GDF11, which showed that the harmful effects of miR-92a be related to its inhibition of GDF11 and subsequent inactivation of the SMAD2/3/FAK/Akt/eNOS signaling pathway. CONCLUSIONS: Inhibiting miR-92a can protect EPCs from HO or HG-induced injury. The effect of miR-92a on EPCs are mediated by regulating of GDF11 and downstream SMAD2/3/FAK/Akt/eNOS signaling pathway.

Transcatheter mitral valve implantation for degenerated mitral bioprostheses or failed surgical annuloplasty rings: A systematic review and meta-analysis.

BACKGROUND: Transcatheter mitral valve-in-valve (TMVIV) and valve-in-ring (TMVIR) implantation for degenerated mitral bioprostheses and failed annuloplasty rings have recently emerged as treatment options for patients deemed unsuitable for repeat surgery. METHODS: A systematic literature review was conducted to summarize the data regarding the baseline characteristics and clinical outcomes of patients undergoing TMVIV and TMVIR procedures. RESULTS: A total of 245 patients (172 patients who underwent TMVIV surgery and 73 patients who underwent TMVIR surgery) were included in the study; 93.5% of patients experienced successful TMVIV or TMVIR implantation. The mortality rates at discharge, 30 days, and 6 months were 5.7%, 8.1%, and 23.4%, respectively. The transapical (TA) access route was used in most procedures (55.2%). The TA and transseptal (TS) access routes resulted in similar outcomes. No significant differences were observed in the short-term outcomes between the patients who developed mitral stenosis versus mitral regurgitation as the mode of failure. CONCLUSIONS: TMVIV and TMVIR implantation for degenerated mitral bioprostheses and failed annuloplasty rings are safe and effective. Both procedures, via TA or TS access, can result in excellent short-term clinical outcomes in patients with mitral stenosis or regurgitation, but long-term follow-up data are currently lacking to determine the durability of these procedures.